There are two things you should know about the inside of your computer.
The computer is not dangerous. You do not have to be an electrician
to work inside one; many people perform computer upgrades themselves at
home. The only component with any significant amount of voltage is the
power supply, and that has its own metal casing so you can't get inside
it anyway. The parts of the system you see run at 5V and 12V DC, which
is no more potent than a transistor radio.
You
are dangerous. You know that little blue spark that zaps from your finger
to the doorknob after walking across the carpet? It carries THOUSANDS
of volts! You know about the static that makes your clothes cling if you
forgot to use fabric softener? That static is worth HUNDREDS of
volts! Remember, most of the computer's circuitry is designed to handle
only 5 volts. If you let static get into the computer, you could blow lots
of tiny fuses and cause mega damage. Therefore, always remember to:
Plug the computer's power cord into a grounded outlet (not
a two-prong outlet)
Make sure the computer is turned off; if you are using a power strip,
turn that off too.
Keep your skin (not your clothes) in contact with a metal part of the
computer's frame, or wear a grounding strap if you have one.